Part Two-Lesson9-10

Part2食品科技英语的阅读,本部分教学内容,Part2食品科技英语的阅读,Lesson9FoodSafety,Part2食品科技英语的阅读,1.1999年比利时的“二噁英”（Dioxin）事件2.2000年英国的“口蹄疫”（Aftosa）事件3.2003年我们亲身经历的“非典”（SAS）事件4.2004年让我们后怕的“禽流感”（birdflu）事件5.2005年啤酒甲醛风波（formaldehyde）6.2006年北京“福寿螺致病”（Goldenapplesnail）事件7.2008年震惊全国的“三鹿奶粉”(Melamine)事件8.,Lesson9FoodSafety,关注食品安全，关心人民健康，是我们每一个食品人的职责和义务！,Part2食品科技英语的阅读,Carcinogenn.致癌物质Aflatoxinn.黄曲霉毒素Herbaln.草药的Alkaloidn.生物碱Rancidityn.酸败Colorantn.着色剂Toxicologicaladj.毒物学的ADI每日摄入量WHO,FAO,FDA,EPA,FTC,FCC,Lesson9FoodSafety,Part2食品科技英语的阅读,Lesson9FoodSafety,Readthefirsttwoparagraphsasfastasyoucanandthenanswerthefollowingquestion:Whatdoes“Somechemicalsshouldbethereandsomeshouldnot”mean?Itmeansthatsomechemicalsshouldbeinthefoodandsomeshouldnotinthefoodintermsoffoodsafety.,Part2食品科技英语的阅读,Thequestion,“Isthefoodsafe?”,usuallyevokesanemotionalresponse.Everybodyhasarighttoasafeandwholesomefoodsupply.Yetthequestionoffoodsafetyisacomplicatedone.,Lesson9FoodSafety,Para.1,Part2食品科技英语的阅读,Theconceptoffoodsafetyhasmanyfacets.Perhapsthemostobvious,andcertainlythemostprevalentproblemoffoodsafetyismicrobiologicalfoodpoisoning.Thisisaseriousprobleminnearlyeverycountry,butanotheraspectoffoodsafetyisprimarilyconcernedwithchemicals.,Lesson9FoodSafety,Para.2,Part2食品科技英语的阅读,foodpoisoning：illnesscausedbybacteriaorothertoxinsinfood,typicallywithvomiting（呕吐）anddiarrhea（腹泻）.慢性中毒急性中毒酒精中毒细菌性食物中毒一氧化碳中毒集体性食物中毒,Lesson9FoodSafety,chronicpoisoningacutepoisoningalcoholicpoisoningbacterialfoodpoisoningcarbonmonoxidepoisoningmasspoisoning,Part2食品科技英语的阅读,Somechemicalsshouldbethereandsomeshouldnot.Chemicalsinourfoodsupplycomefromsixsources.Theseareindustrialaccidents,intentionalfraud,naturalcompounds,foodadditives,pesticides,andenvironmentalpollutants.Allrequireadifferentconceptoffoodsafetyadifferentapproach.,Lesson9FoodSafety,Para.2,Part2食品科技英语的阅读,Theproblemofindustrialaccidentsisdifficultandcomplex.Inourtechnologicalsocietytherewillalwaysbeaccidents.Wehavetogearourlawsandresponsessothattheseunfortunateoccurrencesareminimized.,Lesson9FoodSafety,Para.3,Part2食品科技英语的阅读,Toxicantsoccurringnaturallyinfoodsarenotsubjecttoregulatorycontrol,andmanywouldnotreceiveapprovaliftheywereproposedasfoodadditivesatthelevelsinwhichtheyoccur.,Lesson9FoodSafety,Para.4,Part2食品科技英语的阅读,Someareactuallycarcinogensandwouldnotbeallowedinanyamount.Forexample,theuseofsafrole,aflavoringagentfromthesassafrasroot,isnotpermittedasafoodadditivebecauseofitsassociationwithlivercancer;however,itisnaturallypresentinsmallamountinanumberofspicesnormallyconsumed.,Lesson9FoodSafety,Para.4,Part2食品科技英语的阅读,Aflatoxin,aknowncarcinogenofhighpotency,istheproductofamoldthatoccursonpeanutsandcerealgrains,particularlyinclimatesofhightemperatureandhumidity.Herbalteascontainanumberofpotentiallyharmfulsubstances;someofthem,suchasthealkaloidsymphytineincomfreytea,arecarcinogens.Fortunately,noneoftheseoccurinamountsthatwouldbeharmfulatnormallevelsofuse.,Lesson9FoodSafety,Para.5,Part2食品科技英语的阅读,Thecompoundsaddedtofoodsforspecificpurposearecalledfoodadditives.Examplesareantioxidantsaddedtooilstopreventsrancidity,preservativestopreventfoodfromspoiling,colorantstomakefoodmoreappealing,etc.Mostofthesechemicalsaregenerallyregardedasnecessaryandsafe.,Lesson9FoodSafety,Para.6,Part2食品科技英语的阅读,Pesticidechemicalsareusedintheproductionofplantsandanimals.Manychemicalsareessentialforcontrollinginsectsandfungiinplantsandtopromotebetterhealthinanimals.Residuesmayfindtheirwayintofood.,Lesson9FoodSafety,Para.7,Part2食品科技英语的阅读,Toobtainapprovalofaparticularpesticide,themanufacturermustsupplytheEPAwithdatafromtoxicologicalstudies,residuedata,andjustificationofuseintermsofeconomicsandadequatefoodsupply.Arisk-benefitanalysisleadstorejectionoracceptanceandestablishmentofalegaltolerance.,Lesson9FoodSafety,Para.8,Part2食品科技英语的阅读,Approvalisgrantedonlyforthespecificcommodityapplicationrequested.Forexample,achemicalapprovedforuseonlettucewouldbeconsideredinviolationifusedoncabbageoranyotherfood.Unfortunately,tolerancesarefrequentlysourcesofconsumerconcernwhentheyaremisinterpretedtomeanthelevelsofresiduethatmaybeexpectedinthemarketplace.,Lesson9FoodSafety,Para.8,Part2食品科技英语的阅读,TheFDAalsoroutinelysurveystable-readyfoods.Fourtimeseachyear,234fooditemsrepresentingthedietsofAmericanconsumersarepurchasedindifferentcitiesaroundtheUnitedStates.Thesearepreparedastheywouldbeinthehome,andthenanalyzedforactuallevelsofpesticides,industrialchemicals,heavymetals,radionuclides,andessentialminerals.,Lesson9FoodSafety,Para.9,Part2食品科技英语的阅读,Theintakesforeightage-sexgroupsarecomparedwiththeacceptabledailyintakes(ADI)asestablishedbytheFoodandAgricultureOrganization/WorldHealthOrganizationoftheUnitedNations.(TheADIistheacceptabledailyintakeofachemicalthat,ifingestedoveralifetime,appearstobewithoutappreciablerisk.),Lesson9FoodSafety,Para.9,Part2食品科技英语的阅读,Twenty-fiveyearsofdatahavereportedlevelsofpesticideresidueconsistentlylowerthantheADI.ActualpesticideintakesasdeterminedbytheTotalDietStudiesareusuallyconsiderablylowerthantheADI.,Lesson9FoodSafety,Para.9,Part2食品科技英语的阅读,Environmentpollutantsinland,air,andwatercanappearinfood.Examplesareleadfromgasoline,cadmiumfromindustrialmetalplating,mercuryinfish,fromnaturallyoccurringmercuryintheoceanetc.,Lesson9FoodSafety,Para.10,Part2食品科技英语的阅读,AnumberofgovernmentagenciesshareresponsibilityforthesafetyandhonestmarketingofthefoodsupplyintheUnitedStates.TheFoodandDrugAdministration(FDA)isauthorizedbytheFood,Drug,andCosmeticActtoestablishstandardsofacceptableintakeofaddictivesandcontaminantsinfoodsandtomonitorpesticidelevelsincommoditiesinintrastateshipment.TheFDAalsoregulateslabellingofpackagedfoods.,Lesson9FoodSafety,Para.11,Part2食品科技英语的阅读,TheEnvironmentalProtectionAgency(EPA)establishestolerancesandapprovespesticidesforuse.TheUSDA(UnitedStatesDepartmentofAgriculture)isresponsibleforthewholesomenessofmeatsandpoultry,andtheFederalTradeCommisson(FTC)andFederalcommunicationsCommission(FCC)regulateadvertisingandmarketing.,Lesson9FoodSafety,Para.11,Part2食品科技英语的阅读,1.熟练掌握本文生词和相关组织的全称和缩写2.熟练掌握有关Foodsafety的英文单词和短语如：foodpoisoning，foodadditive，packagedfood，,Lesson9FoodSafety,Part2食品科技英语的阅读,Lesson10Quick-FreezingofFoods,Part2食品科技英语的阅读,Preservationn.保存，储藏Withdrawaln.回收，撤回Immersionn.浸入，浸水Convectionn.传送，运流，对流Multiplatefreezer多层接触式冻结装置Cryogenicadj.制冷的，冷冻的，低温实验法的Fluidizedadj.流态化的，沸腾的fluidizedbed流化床Blanchv.热烫Coatingn.薄层，涂层Rancidityn.脂肪酸败，腐臭Poultryn.家禽,Lesson10Quick-FreezingofFoods,Part2食品科技英语的阅读,Freezingisoneofthemorecommonprocessesforthepreservationoffoods.Thoughithasbeenrecognizedasapreservationtechniqueforseveralhundredyears,themajordevelopmentsinitsutilizationhaveoccurredonlyinthelastcentury.Thepreservationoffoodsbyfreezingdependsontwoprinciples:,Lesson10Quick-FreezingofFoods,Para.1,Part2食品科技英语的阅读,(a)alltypesofchangethatcausedecay,whetherduetolivingmicroorganismsortotheenzymesnaturallypresent,aresloweddownatlowtemperatures;and(b)byfreezingthewaterpresentinfreshfoodsitbecomes,ineffect,withdrawnfromthefoodwhichcanalmostbeconsidered,therefore,tohavebeendried.,Lesson10Quick-FreezingofFoods,Para.1,Part2食品科技英语的阅读,Afurtherprincipleunderlyingthemodernprocessofquick-freezingistherapidwithdrawalofheatleadstoofthewateryfractionofthefoodverysmallcrystalswhichdomuchharmtothestructureofthecommodityfrozenthelargercrystalsproducedwhentherateoffreezingisslow.,Lesson10Quick-FreezingofFoods,Para.1,theconversion,into,less,than,that,Part2食品科技英语的阅读,Fivetypesoffreezingprocessesareusedinmodernfoodtechnology:(a)ImmersionFreezingThefoodstobefrozenareplungeddirectlyintoaverycoldsolution.Atonetimebrinewasemployed,particularlyforfreezingwholefish.Alternativefreezingliquidsthathavemorerecentlycomeintouseareinvertsugarsolutions,particularlyforfruitandvegetables.,Lesson10Quick-FreezingofFoods,Para.2,Part2食品科技英语的阅读,Avariationofimmersionfreezingistheindirectcontactsysteminwhichthefoodisplacedinametalcontainerandthecontainerthenimmersedinabathofrefrigeratedbrineorsomeotherfreezingsolution.,Lesson10Quick-FreezingofFoods,Para.2,Part2食品科技英语的阅读,(b)ConvectionFreezing(c)MultiplateFreezerThisisacabinetwithanumberofhollowshelves,whichformthefreezingsurface.Thefoodtobefrozenisplacedbetweentheshelves,whichpresstogetherontotheitemstobeprocessed.,Lesson10Quick-FreezingofFoods,Para.4,Part2食品科技英语的阅读,(d)CryogenicFreezingThismethodwhichisbeingrapidlydevelopedinvolvestheexposureoffoodtoacoolingmediumataverylowtemperature.Liquidnitrogenatatemperatureof-195.8hasbeenusedsuccessfullyonacommercialscale.Theprinciplemaybeusedinanumberofways.,Lesson10Quick-FreezingofFoods,Para.5,Part2食品科技英语的阅读,Forexample,strawberriesimmersedinliquidnitrogenfor30secondscanbecooledfrom72(23)to10(-12).Alternatively,thefoodtobefrozencanbeexposedtoasprayofliquidnitrogenortoablastoftheverycoldnitrogengas.Therapidfreezingachievedbytheseprocessedcangiveproductsparticularlygoodflavor.,Lesson10Quick-FreezingofFoods,Para.5,Part2食品科技英语的阅读,(e)Fluidized-bedFreezing：Inthisprocess,ablastofcoldairisblownupwardsthroughabedofthefoodtobefrozeninsuchawaythattheportionsoffoodbounceupanddownintheairflowandtheentiremassbehavesalmostasifitwerealiquid.,Lesson10Quick-FreezingofFoods,Para.6,Part2食品科技英语的阅读,Ifthebedisslightlysloping,themassoffoodwillflowalongsupportontheairstreamwithouttheneedforconveyorbeltswhichmaygivemechanicaltroubleandwhichrequirecleaning.,Lesson10Quick-FreezingofFoods,Para.6,Part2食品科技英语的阅读,1.Fruitsandvegetables(a)Blanching：Althoughbacterialactivityisbroughttoahaltatthecustomarytemperaturesatwhichquick-frozenfoodsareheld,manyoftheenzymespresentinvegetablesremainactive.Itis,therefore,necessarytoblanchthesefoods.,Lesson10Quick-FreezingofFoods,Para.7,Part2食品科技英语的阅读,Scaldingforashorttimeinboilingwater,orbriefexposuretolivesteamdestroysmostenzymes.Forsteam-scalding,thewashed,trimmedandotherwisepreparedfruitorvegetablesareconveyedthroughasteam-tunnel.Forwater-scalding,thevegetablesarepassedthroughatankofboilingwater.,Lesson10Quick-FreezingofFoods,Para.7,Part2食品科技英语的阅读,Theenzymeperoxidasesurvivesheattreatmentforlongerthanmanyothers.Itisusual,therefore,whentheconditionsforquick-freezinganewproductarebeingestablished,tocontinueblanchinguntilanegativechemicalreactionforperoxidaseisobtained.,Lesson10Quick-FreezingofFoods,Para.8,Part2食品科技英语的阅读,Theperoxidasetestisdonebyputtingaspotofafreshlymadesolutionof1%guaiacolmixedwithanequalamountofhydrogenperoxide(fivevolumesstrength)ontothefood.Ifperoxidaseisstillpresent,areddish-browncolorappearswithin1minute.,Lesson10Quick-FreezingofFoods,Para.8,Part2食品科技英语的阅读,(b)Freezing:Forfreezing,thefood,whichmaybepackedincartonsorwrappedinplasticfilm,iscooledto23(-10)to-35(-30)inasshortatimeaspossible.Oncethefoodisfrozen,itisnotnecessarytomaintainitattheselowtemperatures.,Lesson10Quick-FreezingofFoods,Para.9,-,Part2食品科技英语的阅读,(c)Storage:Storageshouldbeatabout-20(-4).Evenatthistemperature,somechangesoccur.Forexample,alossofupto20%inthegreenchlorophyllinfrozengreenbeansmayoccurinsixmonths,andthislossincreasesinspeedfourtofivetimesforeach6(42)riseintemperature.,Lesson10Quick-FreezingofFoods,Para.10,Part2食品科技英语的阅读,Itfollowsthatitisofmuchimportanceforquick-frozenfoodstobeheldatlowtemperatures.Seriousdeteriorationcanoccurif,forexample,thestoragecabinetsinretailstoresareinefficient,asissometimesfound.,Lesson10Quick-FreezingofFoods,Para.10,Part2食品科技英语的阅读,(d)VitaminCContent:ThevitaminCcontentofproperlyprocessedquick-frozenfruitandvegetablesisoftensuperiortothatoffreshmaterialasobtainedinthemarket,duetotherigorousselectionofsoundmaterialforfreezing.,Lesson10Quick-FreezingofFoods,Para.11,Part2食品科技英语的阅读,LossesofvitaminCoccurasfollows:(i)Blanchingmaycausealossof10-20%;(ii)Foodstoredat-20(-4)willlose50%ofitsvitaminCinayear;(iii)Four-tofive-foldlossoccursforeach6(42)riseinstoragetemperature.,Lesson10Quick-FreezingofFoods,Para.11,Part2食品科技英语的阅读,2.Fish：Frozenfoodsareofimportanceinmodernfoodtechnologybecausewhenproperlystoredatappropriatelowtemperaturetheycanbekeptforayearorsometimemore.Butafurtheradvantageisthattheyare“foodsofconvenience”.,Lesson10Quick-FreezingofFoods,Para.12,Part2食品科技英语的阅读,Thecarefullychosenandpreparedfoodswhichcanusuallybetakendirectlyfromacartonandputintothecookingvesselor,inthecaseoffruitsuchasstrawberries,simplyallowedtothawandtheneaten,avoidingtheneedforanytroubletocookorhousewife.,Lesson10Quick-FreezingofFoods,Para.12,Part2食品科技英语的阅读,Ofallunprocessedfoods,fishisperhapsthemostinconvenient,beingofuncertainquality,highlyperishable,troublesometoprepare,difficulttocookwellandnoteasytokeephotifnotneededimmediately.Forthisreason,preparedfishportionsquick-frozenhavebecomeamajorarticleofcommerce.Theyareknownas“fishfingers”inGreatBritainand“fishsticks”inAmerica.,Lesson10Quick-FreezingofFoods,Para.12,Part2食品科技英语的阅读,Theyareprocessedasfollows:(a)PreparationofPortions：Skinnedfilletsofcodorhaddockaretightlypackedintorectangularcardboardboxesofstandarddimensions:20121.5in.isaconvenientsize.Theboxesarefrozeninapressure-platefreezer.,Lesson10Quick-FreezingofFoods,Para.13,Part2食品科技英语的阅读,Theblocksoffrozenfisharecutupinto“sticks”,47/85/8in.,orintoportions,42.55/8in.Mechanicalstainless-steelbandsawsmaybeusedbutcauseacertainlossoffishassawdust.Thismaybeavoidedbytheuseofguillotine.,Lesson10Quick-FreezingofFoods,Para.13,Part2食品科技英语的阅读,(b)Coating：Thepiecesoffish